Not all bacteria cause disease & Damage and transmission routes

Not all bacteria cause disease

Bacteria are tiny single-celled organisms occurring in many environments and on or inside the human body. They may be round, rod-shaped, or spiral-shaped. Most types do not cause illness. Digestive bacteria can support food processing and nutrient absorption, and bacteria help produce yogurt or cheese. Their presence alone does not prove infection. Eliminating all bacteria would not be equivalent to protecting health because some perform useful functions.

Damage and transmission routes

Some bacteria multiply rapidly, release toxins, or invade tissues and cause damage. Spread can occur through respiratory droplets, contaminated objects, wounds, skin contact, food, or water. Sexual contact, animal or insect bites, and transmission during pregnancy are routes for some infections. The route varies with the organism. Prevention therefore needs to address the actual exposure rather than assuming one identical method explains every bacterial illness.

Key concepts

Not all bacteria cause disease

Bacteria are tiny single-celled organisms occurring in many environments and on or inside the human body.

Damage and transmission routes

Some bacteria multiply rapidly, release toxins, or invade tissues and cause damage.

Antibiotics act on susceptible bacteria

Antibiotics kill bacteria or stop their growth and multiplication.

Resistance and responsible use

Resistance occurs when bacteria change so an antibiotic is less effective against them.

References

• MedlinePlus en español — Bacteria, Infection, and Antibiotic Resistance